Link quality estimation is useful for link types other than wireless, especially when using babel with tunnels where packet losses do occur. Changes since v1: - fix missing reference to link quality in example configuration - fix mishandling of default configuration --- doc/bird.sgml | 7 +++++++ proto/babel/babel.c | 19 ++++++------------- proto/babel/babel.h | 1 + proto/babel/config.Y | 8 +++++++- 4 files changed, 21 insertions(+), 14 deletions(-) diff --git a/doc/bird.sgml b/doc/bird.sgml index 8041faa9..e597de83 100644 --- a/doc/bird.sgml +++ b/doc/bird.sgml @@ -1929,6 +1929,7 @@ protocol babel [<name>] { rx buffer <number>; tx length <number>; check link <switch>; + link quality <switch>; next hop ipv4 <address>; next hop ipv6 <address>; extended next hop <switch>; @@ -2032,6 +2033,12 @@ protocol babel [<name>] { hardware drivers or platforms do not implement this feature. Default: yes. + <tag><label id="babel-link-quality">link quality <m/switch/</tag> + If set, link quality estimation is performed on this interface. + Link quality is measured by packet loss and is used for computing + metrics of routes going through this interface. Default: yes for + wireless interfaces, no otherwise. + <tag><label id="babel-next-hop-ipv4">next hop ipv4 <m/address/</tag> Set the next hop address advertised for IPv4 routes advertised on this interface. Default: the preferred IPv4 address of the interface. diff --git a/proto/babel/babel.c b/proto/babel/babel.c index 7f0cca73..6a238d75 100644 --- a/proto/babel/babel.c +++ b/proto/babel/babel.c @@ -593,21 +593,15 @@ babel_update_cost(struct babel_neighbor *nbr) if (!rcv || !nbr->ifa->up) goto done; - switch (cf->type) - { - case BABEL_IFACE_TYPE_WIRED: - case BABEL_IFACE_TYPE_TUNNEL: + if (!cf->link_quality) { /* k-out-of-j selection - Appendix 2.1 in the RFC. */ /* Link is bad if less than cf->limit/16 of expected hellos were received */ - if (rcv * 16 < cf->limit * max) - break; - - rxcost = cf->rxcost; - txcost = nbr->txcost; - break; - - case BABEL_IFACE_TYPE_WIRELESS: + if (!(rcv * 16 < cf->limit * max)) { + rxcost = cf->rxcost; + txcost = nbr->txcost; + } + } else { /* * ETX - Appendix 2.2 in the RFC. * @@ -622,7 +616,6 @@ babel_update_cost(struct babel_neighbor *nbr) */ rxcost = MIN( cf->rxcost * max / rcv, BABEL_INFINITY); txcost = MIN(nbr->txcost * max / rcv, BABEL_INFINITY); - break; } if (cf->rtt_cost && nbr->srtt > cf->rtt_min) diff --git a/proto/babel/babel.h b/proto/babel/babel.h index edde4cab..6145bb58 100644 --- a/proto/babel/babel.h +++ b/proto/babel/babel.h @@ -145,6 +145,7 @@ struct babel_iface_config { u8 type; u8 limit; /* Minimum number of Hellos to keep link up */ u8 check_link; + u8 link_quality; /* bool + 2 for unspecified */ uint port; uint hello_interval; /* Hello interval, in us */ uint ihu_interval; /* IHU interval, in us */ diff --git a/proto/babel/config.Y b/proto/babel/config.Y index b8af0267..4a3d33cb 100644 --- a/proto/babel/config.Y +++ b/proto/babel/config.Y @@ -26,7 +26,7 @@ CF_KEYWORDS(BABEL, INTERFACE, METRIC, RXCOST, HELLO, UPDATE, INTERVAL, PORT, TYPE, WIRED, WIRELESS, RX, TX, BUFFER, PRIORITY, LENGTH, CHECK, LINK, NEXT, HOP, IPV4, IPV6, BABEL_METRIC, SHOW, INTERFACES, NEIGHBORS, ENTRIES, RANDOMIZE, ROUTER, ID, AUTHENTICATION, NONE, MAC, PERMISSIVE, - EXTENDED, TUNNEL, RTT, MIN, MAX, DECAY, SEND, TIMESTAMPS) + EXTENDED, TUNNEL, RTT, MIN, MAX, DECAY, SEND, TIMESTAMPS, QUALITY) CF_GRAMMAR @@ -72,6 +72,7 @@ babel_iface_start: BABEL_IFACE->rtt_decay = BABEL_RTT_DECAY; BABEL_IFACE->rtt_send = 1; BABEL_IFACE->check_link = 1; + BABEL_IFACE->link_quality = 2; BABEL_IFACE->ext_next_hop = 1; }; @@ -84,6 +85,8 @@ babel_iface_finish: BABEL_IFACE->hello_interval = BABEL_HELLO_INTERVAL_WIRELESS; if (!BABEL_IFACE->rxcost) BABEL_IFACE->rxcost = BABEL_RXCOST_WIRELESS; + if (BABEL_IFACE->link_quality == 2) + BABEL_IFACE->link_quality = 1; } else { @@ -93,6 +96,8 @@ babel_iface_finish: BABEL_IFACE->rxcost = BABEL_RXCOST_WIRED; if (BABEL_IFACE->type == BABEL_IFACE_TYPE_TUNNEL && !BABEL_IFACE->rtt_cost) BABEL_IFACE->rtt_cost = BABEL_RXCOST_RTT; + if (BABEL_IFACE->link_quality == 2) + BABEL_IFACE->link_quality = 0; } if (BABEL_IFACE->rtt_cost && !BABEL_IFACE->rtt_send) @@ -156,6 +161,7 @@ babel_iface_item: | TX tos { BABEL_IFACE->tx_tos = $2; } | TX PRIORITY expr { BABEL_IFACE->tx_priority = $3; } | CHECK LINK bool { BABEL_IFACE->check_link = $3; } + | LINK QUALITY bool { BABEL_IFACE->link_quality = $3; } | NEXT HOP IPV4 ipa { BABEL_IFACE->next_hop_ip4 = $4; if (!ipa_is_ip4($4)) cf_error("Must be an IPv4 address"); } | NEXT HOP IPV6 ipa { BABEL_IFACE->next_hop_ip6 = $4; if (!ipa_is_ip6($4)) cf_error("Must be an IPv6 address"); } | EXTENDED NEXT HOP bool { BABEL_IFACE->ext_next_hop = $4; } -- 2.41.0